1. Field of the Invention
The present invention relates to an apparatus and method for managing quality of service (QoS) in an integrated network system; and, more particularly, to an apparatus and method for effectively managing QoS in an integrated network system by calculating conditions that are based of a policy using a user profile and network information, deciding a network equipment control algorithm using the calculated conditions, and processing a service using a policy corresponding the decided network equipment control algorithm in a 3rd generation (3G) mobile communication system that is operated by various radio access technologies (RAT).
This work was supported by the Information Technology (IT) research and development program of the Korean Ministry of Information and Communication (MIC) and the Korean Institute for Information Technology Advancement (IITA) [2005-S-404-22, “Research and development on 3G long-term evolution access system”].
2. Description of Related Art
Throughout the specification, a 3GPP long term evolution (LTE) system will be described as an example of an integrated network system.
The 3rd generation partnership project (3GPP), the international standard organization, introduced 3GPP long term evolution (LTE). The 3GPP LTE is a name given to a project to improve a current mobile communication system to a new 3rd generation mobile communication system to cope with future requirements. Related mobile communication standard has been in progress by the 3GPP.
Unlike a general system where a 3rd generation single network independently exists, it is expected that a user's demand for QoS will be more complicated in a future mobile communication system. Particularly, the mobility support has been receiving attention as one of major issue for enabling users to travel through various heterogeneous systems with one terminal. Even in the 3GPP LTE, there have been many studies in progress for supporting the mobility.
It is expected that a 3GPP LTE system will have an integrated network structure where a mobile communication network and a wired network are integrated. In the integrated network, a mobile communication network, x digital subscriber line (xDSL), wired home network, public switched telephone network (PSTN), and hot spot based wireless network mutually operate. Such a wired and wireless integrated network may use Internet protocol to mutually operate.
In the internet, services are generally provided based on a best-effort transmission scheme. The best-effort transmission scheme is not sufficient to satisfy further complicated QoS demands. In order to satisfy further complex QoS demands, integrated services (IntServ) scheme, a differentiated services (DiffServ) scheme, a Next Step in Signaling (NSIS) scheme, a Multi-Protocol Label Switching (MPLS) scheme were introduced. Such schemes are a method for guaranteeing QoS in a wireless IP network. These schemes will be described, hereinafter.
The IntServ scheme describes the characteristics of traffic and service requirements and provides QoS for each service session based on the description in order to provide point-to-point QoS for various IP applications. Also, the IntServ scheme performs a signaling procedure using a resource reservation protocol (RSVP) for reserving resources according to user's QoS requirement and transmits user traffic.
An application to establish connection starts a RSVP procedure for reserving resources and transfers requested RSVP QoS request information to a policy control module and an admission control module. Then, the admission control module decides whether corresponding resources are allocated or not based on the requested QoS information, and a RSVP process module interacts with the policy control module for confirming a permission of a user requesting the corresponding resources.
After the policy control module and the admission control module end the resource allocation confirm procedure, the RSVP processor module sets a parameter for a QoS service requested from a packet classifier and a packet scheduler. The packet classifier sorts data packets belonging to different QoS classes, and the packet scheduler performs a scheduling function of packets outputted according to the QoS parameter set by the RSVP processor.
The DiffServ scheme was introduced to compensate the problem of the IntServ scheme. The DiffServ scheme provides distinct services by classifying packets according to a class of traffic at an edge node of a network. The state of traffic is managed only at the edge node of a network, and a router on a path does not include resource reservation information.
Also, the DiffServ scheme has more scalability than the IntServ scheme because routers in a core network perform scheduling and buffer managing functions for one aggregated flow by gathering a plurality of flows.
Since the DiffServ scheme does not include a signaling procedure for one-to-one QoS, the complexity of the DiffServ scheme is lower than the IntServ scheme and the RSVP scheme.
The MPLS scheme is a mechanism applying connection oriented used in an asynchronous transfer mode (ATM) network and a frame relay network to an Internet using a hop by hop transmission scheme. The MPLS scheme sets a virtual circuit using a signaling protocol before data packet is transmitted and provides QoS mechanisms transmitting user data traffic.
Such a MPLS scheme inserts a fixed length of a label to a packet header and transmits the packet. A label switching router (LSR) receives the packet, and performs routing by deciding a next hop through the header of the received packet. On MPLS domain, the transmission path of packets is defined as a label switched path (LSP), and a LSP is decided by setting a label value at the first LSR.
Finally, the basic concept of the MPLS is a forwarding structure through exchanging labels by interacting with different control modules, and each control module allocates and distributes labels.
The NSIS scheme is a field that related standards has been developed by ‘IETF NSIS WG’. The NSIS scheme is an IP signaling protocol system for providing guaranteed QoS in an IP network that provides services in the best effort scheme.
Although NSIS protocol was defined as a signaling protocol for end-to-end QoS that reuses a proper part of initial RSVP, the NSIS protocol has been redefined to a protocol setting constant state information to various constituent elements in a network. Accordingly, the NSIS protocol is hierarchically divided into a NSIS transport layer protocol (NTLP) as a common transfer protocol and a NSIS signaling layer protocol (NSLP) which is a signaling protocol by application such as QoS application, and middle box control application such as firewall.
As described above, the NSIS scheme includes a NTLP layer and a NSLP layer. The NTLP layer is a common part for various NSIS application signaling protocols and operates as a transfer layer to transfer. The application protocol of the NTLP includes a resource reservation protocol for QoS and a middle box control protocol for setting traffic to pass middle box on a network path, such as a network address translator (NAT) and a firewall (FW).
The NSIS scheme defines new state information setting in any form in network equipment as an application of a signaling protocol, for example, resource reservation for QoS, and flow setting for passing NAT/FW.
Finally, signaling application protocols are commonly referred as a NSLP. Such NSIS has generally two layer structure.
Although such conventional technologies can effectively manage and provide QoS using a method evolved from the best-effect service providing scheme, its target object is only a wired IP network, and has constraint in flexibility. Therefore, it is difficult to apply such conventional technologies to heterogeneous integrated system.
In order to overcome such shortcoming, a policy based network management (PBNM) was introduced for quarantining and easily managing complicated and various QoS.
The PBNM introduced by IETF is a network management scheme for effectively managing QoS. The basic policy defined by the PBNM as follow.
‘If condition, then action’
It means management/operation based on policy. A predetermined operation is performed for a previously defined condition. In order to perform such operations, numerous and various conditions and operations are defined previously.
However, it is not easy to build huge amounts of data before a system operates. Although policies are prepared for maximum predictably situations, some unpredictable events will occur. In this case, a network operator makes a new policy. If a policy for a generated event is not prepared previously, the closest policy is used. If the closest policy is not proper, a new policy is derived in real time through learning.
The PBNM includes a policy decision point (PDP), a policy repository (PR), and a policy enforcement point (PEP).
The PBNM will be described in more detail.
The PDP decides a policy. That is, if a predetermined event occurs, the PDP decides an optimal policy in consideration of various variables. The policy is defined according to conditions before event occurs. The PR stores the policy.
That is, when a predetermined event is generated, the PTP makes policy candidate groups in consideration of corresponding variables and selects the optimal policy from the policy candidate groups. Such policies may be embodied as database, and can be searched in the PR.
The decided policy is transferred to a network constituent element and instructs the network constituent element to perform a predetermined action. The PEP performs a sequence of operations defined according to the policy decision. Herein, the PDP, the PEP, and the PR denote only conceptual functions. These are not newly added physical units on a network.
In LTE standard introduced by 3GPP, Policy and Charging Rule Function (PCRF) was introduced. The PCRF performs a function similar to the PDP. That is, the PCRF manages policies for managing and providing QoS and manages billing. The basic concept was developed from Internet Engineering Task Force (IETF). However, a procedure for deciding a policy for managing QoS is not clearly described. Also, a procedure for interacting with the PR and the PER until policy is valid, is not described neither. Furthermore, the PR or the PEP was not described at all.
Therefore, there is a demand for developing a method for newly defining the functions of the PR and the PEP and deriving a real policy through interacting with the PR and the PEP in an integrated network such as a 3GPP LTE system using Policy and Charging Rule Function (PCRF).